source4/wrepl_server/wrepl_server.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    WINS Replication server
   5
   6    Copyright (C) Stefan Metzmacher      2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24 #include "dlinklist.h"
  25 #include "lib/events/events.h"
  26 #include "lib/socket/socket.h"
  27 #include "smbd/service_task.h"
  28 #include "smbd/service_stream.h"
  29 #include "lib/messaging/irpc.h"
  30 #include "librpc/gen_ndr/ndr_winsrepl.h"
  31 #include "wrepl_server/wrepl_server.h"
  32
  33 void wreplsrv_terminate_connection(struct wreplsrv_in_connection *wreplconn, const char *reason)
  34 {
  35         stream_terminate_connection(wreplconn->conn, reason);
  36 }
  37
  38 /*
  39   called when we get a new connection
  40 */
  41 static void wreplsrv_accept(struct stream_connection *conn)
  42 {
  43         struct wreplsrv_service *service = talloc_get_type(conn->private, struct wreplsrv_service);
  44         struct wreplsrv_in_connection *wreplconn;
  45
  46         wreplconn = talloc_zero(conn, struct wreplsrv_in_connection);
  47         if (!wreplconn) {
  48                 stream_terminate_connection(conn, "wreplsrv_accept: out of memory");
  49                 return;
  50         }
  51
  52         wreplconn->conn         = conn;
  53         wreplconn->service      = service;
  54         wreplconn->our_ip       = socket_get_my_addr(conn->socket, wreplconn);
  55         if (!wreplconn->our_ip) {
  56                 wreplsrv_terminate_connection(wreplconn, "wreplsrv_accept: out of memory");
  57                 return;
  58         }
  59
  60         /* TODO: find out if it's a partner */
  61
  62         conn->private = wreplconn;
  63
  64         irpc_add_name(conn->msg_ctx, "wreplsrv_connection");
  65 }
  66
  67 /*
  68   receive some data on a WREPL connection
  69 */
  70 static void wreplsrv_recv(struct stream_connection *conn, uint16_t flags)
  71 {
  72         struct wreplsrv_in_connection *wreplconn = talloc_get_type(conn->private, struct wreplsrv_in_connection);
  73         struct wreplsrv_in_call *call;
  74         DATA_BLOB packet_in_blob;
  75         DATA_BLOB packet_out_blob;
  76         struct wrepl_wrap packet_out_wrap;
  77         struct data_blob_list_item *rep;
  78         NTSTATUS status = NT_STATUS_UNSUCCESSFUL;
  79         size_t nread;
  80
  81         /* avoid recursion, because of half async code */
  82         if (wreplconn->processing) {
  83                 EVENT_FD_NOT_READABLE(conn->event.fde);
  84                 return;
  85         }
  86
  87         if (wreplconn->partial.length == 0) {
  88                 wreplconn->partial = data_blob_talloc(wreplconn, NULL, 4);
  89                 if (wreplconn->partial.data == NULL) {
  90                         status = NT_STATUS_NO_MEMORY;
  91                         goto failed;
  92                 }
  93                 wreplconn->partial_read = 0;
  94         }
  95
  96         /* read in the packet length */
  97         if (wreplconn->partial_read < 4) {
  98                 uint32_t packet_length;
  99
 100                 status = socket_recv(conn->socket,
 101                                      wreplconn->partial.data + wreplconn->partial_read,
 102                                      4 - wreplconn->partial_read,
 103                                      &nread, 0);
 104                 if (NT_STATUS_IS_ERR(status)) goto failed;
 105                 if (!NT_STATUS_IS_OK(status)) return;
 106
 107                 wreplconn->partial_read += nread;
 108                 if (wreplconn->partial_read != 4) return;
 109
 110                 packet_length = RIVAL(wreplconn->partial.data, 0) + 4;
 111
 112                 wreplconn->partial.data = talloc_realloc(wreplconn, wreplconn->partial.data,
 113                                                          uint8_t, packet_length);
 114                 if (wreplconn->partial.data == NULL) {
 115                         status = NT_STATUS_NO_MEMORY;
 116                         goto failed;
 117                 }
 118                 wreplconn->partial.length = packet_length;
 119         }
 120
 121         /* read in the body */
 122         status = socket_recv(conn->socket,
 123                              wreplconn->partial.data + wreplconn->partial_read,
 124                              wreplconn->partial.length - wreplconn->partial_read,
 125                              &nread, 0);
 126         if (NT_STATUS_IS_ERR(status)) goto failed;
 127         if (!NT_STATUS_IS_OK(status)) return;
 128
 129         wreplconn->partial_read += nread;
 130         if (wreplconn->partial_read != wreplconn->partial.length) return;
 131
 132         packet_in_blob.data = wreplconn->partial.data + 4;
 133         packet_in_blob.length = wreplconn->partial.length - 4;
 134
 135         call = talloc_zero(wreplconn, struct wreplsrv_in_call);
 136         if (!call) {
 137                 status = NT_STATUS_NO_MEMORY;
 138                 goto failed;
 139         }
 140         call->wreplconn = wreplconn;
 141
 142         /* we have a full request - parse it */
 143         status = ndr_pull_struct_blob(&packet_in_blob,
 144                                       call, &call->req_packet,
 145                                       (ndr_pull_flags_fn_t)ndr_pull_wrepl_packet);
 146         if (!NT_STATUS_IS_OK(status)) {
 147                 DEBUG(2,("Failed to parse incoming WINS-Replication packet - %s\n",
 148                          nt_errstr(status)));
 149                 DEBUG(10,("packet length %u\n", wreplconn->partial.length));
 150                 NDR_PRINT_DEBUG(wrepl_packet, &call->req_packet);
 151                 goto failed;
 152         }
 153
 154         /*
 155          * we have parsed the request, so we can reset the wreplconn->partial_read,
 156          * maybe we could also free wreplconn->partial, but for now we keep it,
 157          * and overwrite it the next time
 158          */
 159         wreplconn->partial_read = 0;
 160
 161         if (DEBUGLVL(10)) {
 162                 DEBUG(10,("Received WINS-Replication packet of length %u\n", wreplconn->partial.length));
 163                 NDR_PRINT_DEBUG(wrepl_packet, &call->req_packet);
 164         }
 165
 166         /* actually process the request */
 167         wreplconn->processing = True;
 168         status = wreplsrv_in_call(call);
 169         wreplconn->processing = False;
 170         if (NT_STATUS_IS_ERR(status)) goto failed;
 171         if (!NT_STATUS_IS_OK(status)) {
 172                 /* w2k just ignores invalid packets, so we do */
 173                 DEBUG(10,("Received WINS-Replication packet was invalid, we just ignore it\n"));
 174                 talloc_free(call);
 175                 return;
 176         }
 177
 178         /* and now encode the reply */
 179         packet_out_wrap.packet = call->rep_packet;
 180         status = ndr_push_struct_blob(&packet_out_blob, call, &packet_out_wrap,
 181                                       (ndr_push_flags_fn_t)ndr_push_wrepl_wrap);
 182         if (!NT_STATUS_IS_OK(status)) goto failed;
 183
 184         if (DEBUGLVL(10)) {
 185                 DEBUG(10,("Sending WINS-Replication packet of length %d\n", (int)packet_out_blob.length));
 186                 NDR_PRINT_DEBUG(wrepl_packet, &call->rep_packet);
 187         }
 188
 189         rep = talloc(wreplconn, struct data_blob_list_item);
 190         if (!rep) {
 191                 status = NT_STATUS_NO_MEMORY;
 192                 goto failed;
 193         }
 194
 195         rep->blob = packet_out_blob;
 196         talloc_steal(rep, packet_out_blob.data);
 197         /* we don't need the call anymore */
 198         talloc_free(call);
 199
 200         if (!wreplconn->send_queue) {
 201                 EVENT_FD_WRITEABLE(conn->event.fde);
 202         }
 203         DLIST_ADD_END(wreplconn->send_queue, rep, struct data_blob_list_item *);
 204
 205         if (wreplconn->terminate) {
 206                 EVENT_FD_NOT_READABLE(conn->event.fde);
 207         } else {
 208                 EVENT_FD_READABLE(conn->event.fde);
 209         }
 210         return;
 211
 212 failed:
 213         wreplsrv_terminate_connection(wreplconn, nt_errstr(status));
 214 }
 215
 216 /*
 217   called when we can write to a connection
 218 */
 219 static void wreplsrv_send(struct stream_connection *conn, uint16_t flags)
 220 {
 221         struct wreplsrv_in_connection *wreplconn = talloc_get_type(conn->private, struct wreplsrv_in_connection);
 222         NTSTATUS status;
 223
 224         while (wreplconn->send_queue) {
 225                 struct data_blob_list_item *rep = wreplconn->send_queue;
 226                 size_t sendlen;
 227
 228                 status = socket_send(conn->socket, &rep->blob, &sendlen, 0);
 229                 if (NT_STATUS_IS_ERR(status)) goto failed;
 230                 if (!NT_STATUS_IS_OK(status)) return;
 231
 232                 rep->blob.length -= sendlen;
 233                 rep->blob.data   += sendlen;
 234
 235                 if (rep->blob.length == 0) {
 236                         DLIST_REMOVE(wreplconn->send_queue, rep);
 237                         talloc_free(rep);
 238                 }
 239         }
 240
 241         if (wreplconn->terminate) {
 242                 wreplsrv_terminate_connection(wreplconn, "connection terminated after all pending packets are send");
 243                 return;
 244         }
 245
 246         EVENT_FD_NOT_WRITEABLE(conn->event.fde);
 247         return;
 248
 249 failed:
 250         wreplsrv_terminate_connection(wreplconn, nt_errstr(status));
 251 }
 252
 253 static const struct stream_server_ops wreplsrv_stream_ops = {
 254         .name                   = "wreplsrv",
 255         .accept_connection      = wreplsrv_accept,
 256         .recv_handler           = wreplsrv_recv,
 257         .send_handler           = wreplsrv_send,
 258 };
 259
 260 /*
 261   startup the wrepl port 42 server sockets
 262 */
 263 static NTSTATUS wreplsrv_setup_sockets(struct wreplsrv_service *service)
 264 {
 265         NTSTATUS status;
 266         struct task_server *task = service->task;
 267         const struct model_ops *model_ops;
 268         const char *address;
 269         uint16_t port = WINS_REPLICATION_PORT;
 270
 271         /* within the wrepl task we want to be a single process, so
 272            ask for the single process model ops and pass these to the
 273            stream_setup_socket() call. */
 274         model_ops = process_model_byname("single");
 275         if (!model_ops) {
 276                 DEBUG(0,("Can't find 'single' process model_ops"));
 277                 return NT_STATUS_INTERNAL_ERROR;
 278         }
 279
 280         if (lp_interfaces() && lp_bind_interfaces_only()) {
 281                 int num_interfaces = iface_count();
 282                 int i;
 283
 284                 /* We have been given an interfaces line, and been
 285                    told to only bind to those interfaces. Create a
 286                    socket per interface and bind to only these.
 287                 */
 288                 for(i = 0; i < num_interfaces; i++) {
 289                         address = iface_n_ip(i);
 290                         status = stream_setup_socket(task->event_ctx, model_ops, &wreplsrv_stream_ops,
 291                                                      "ipv4", address, &port, NULL);
 292                         if (!NT_STATUS_IS_OK(status)) {
 293                                 DEBUG(0,("stream_setup_socket(address=%s,port=%u) failed - %s\n",
 294                                          address, port, nt_errstr(status)));
 295                                 return status;
 296                         }
 297                 }
 298         } else {
 299                 address = lp_socket_address();
 300                 status = stream_setup_socket(task->event_ctx, model_ops, &wreplsrv_stream_ops,
 301                                              "ipv4", address, &port, NULL);
 302                 if (!NT_STATUS_IS_OK(status)) {
 303                         DEBUG(0,("stream_setup_socket(address=%s,port=%u) failed - %s\n",
 304                                  address, port, nt_errstr(status)));
 305                         return status;
 306                 }
 307         }
 308
 309         return NT_STATUS_OK;
 310 }
 311
 312 /*
 313   startup the wrepl task
 314 */
 315 static void wreplsrv_task_init(struct task_server *task)
 316 {
 317         NTSTATUS status;
 318         struct wreplsrv_service *service;
 319
 320         service = talloc_zero(task, struct wreplsrv_service);
 321         if (!service) {
 322                 task_server_terminate(task, "wreplsrv_task_init: out of memory");
 323                 return;
 324         }
 325         service->task = task;
 326         task->private = service;
 327
 328         /*
 329          * TODO: setup up all partners, and open the winsdb
 330          */
 331
 332         /*
 333          * setup listen sockets, so we can anwser requests from our partners,
 334          * which pull from us
 335          */
 336         status = wreplsrv_setup_sockets(service);
 337         if (!NT_STATUS_IS_OK(status)) {
 338                 task_server_terminate(task, "wreplsrv_task_init: wreplsrv_setup_sockets() failed");
 339                 return;
 340         }
 341
 342         /*
 343          * TODO: setup timed events for each partner we want to pull from
 344          */
 345
 346         irpc_add_name(task->msg_ctx, "wrepl_server");
 347 }
 348
 349 /*
 350   initialise the WREPL server
 351  */
 352 static NTSTATUS wreplsrv_init(struct event_context *event_ctx, const struct model_ops *model_ops)
 353 {
 354         return task_server_startup(event_ctx, model_ops, wreplsrv_task_init);
 355 }
 356
 357 /*
 358   register ourselves as a available server
 359 */
 360 NTSTATUS server_service_wrepl_init(void)
 361 {
 362         return register_server_service("wrepl", wreplsrv_init);
 363 }